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Information × Registration Number 0201U003652, 0199U004412 , R & D reports Title Physical properties and the problems of origin of asteroids and comets popup.stage_title Head Lupishko D.F., Registration Date 03-04-2001 Organization Kharkov National University named after V.N. Karazin popup.description2 Objects of investigations — main-belt asteroids, near-Earth asteroids (NEA) and comets. Purpose of the project is determinationof the shapes, sizes, spin-vectors and optical properties of main-belt and near-Earth asteroids; a study of optical properties of comets and of the nature of their dust particles; a determination of sources of NEA origin. Methods of research — photometry, polarimetry and mathematical modeling. The photometric and polarimetric observations of 32 asteroids and two comets were carried out. The magnitudes, color indexes, lightcurve amplitudes and parameters of polarization have been obtained for these objects. The rotation periods of nine asteroids, the size estimates of NEAs 1999 CV3 and 1999 US3 and pole coordinates of 1999 CV3 were determined for the first time. Over 200 of astrometric positions of the asteroids were determined and sent to the International Minor Planet Center (USA). A desintegration of nucleus of comet C/1999 S4 (LINEAR) was stated which was confirmed by an abn ormal increase of positive polarization in its maximum and by observational data abroad. Anomalous spectral behavior of positive polarization for comet 21P/Giacobini-Zinner was detected. It is explained by a presence of a high content of organic in the comet dust particles. Using numerical modeling it was shown that displacement of asteroid photocentre relatively the geometrical one to a large measure depends on the asteroid shape, phase angle and light scattering properties. The proposed method of displacement determination and taking into account allow us to increase the accuracy of asteroid position determination. On the basis of comparative analysis of physical properties of main-belt asteroids, NEAs and comets it was shown that the main asteroid belt is the principal source of NEA replenishment and a fraction of NEAs of cometary origin does not exceed 10%. Obtained resuits are of great interest from the point of view of both fundamental science and the asteroid hazard problem. The lightcurves and parame ters of polarization obtained in this project will be included to the international database "Asteroid Photometric Catalogue" and "Planetary Data System", respectively. Product Description popup.authors popup.nrat_date 2020-04-02 Close